DME is non-toxic and is currently used as aerosol propellants and refrigerant as a substitute of chlorofluorocarbons. The property of DME is very attractive as a substitute of LPG and diesel oil and as a clean fuel without SOx and smoke.
DME's boiling point at ambient pressure (−24.6° C.) is below minus and close to LPG as C3H8 (−42.1° C.) which is easily liquefied and stored. LPG existing infrastructure such as tank and refrigerated tanker could be used with minor modification. DME cetane number (55-60) is very similar to diesel oil (38-53). DME could be used in diesel engines with minor modification.
DME is currently produced indirectly by dehydration of methanol in small scale plants in total with an order of 250,000 MT/Y in the world. On the contrary, DME is multi-source energy and could be mass-produced directly in one step from syngas converted from various feedstocks such as natural gas, fuel oil, coal, biomass, etc. Recently there are announcements of many projects being planned to start commercial operation using the DME direct synthesis route.
In this invention, a process of economically and efficiently producing DME in direct route is disclosed.